【摘要】：超臨界沉積物重力流是指在深水環(huán)境中弗洛德數(shù)大于1,沿水下斜坡向盆地中心搬運、在水力跳躍機制作用下發(fā)生超臨界流與亞臨界流頻繁轉(zhuǎn)化、形成易于保存的大型波狀旋回坎的高密度流。超臨界沉積物重力流作用的沉積識別標志主要包括牽引毯作用形成的分層構(gòu)造,即后積層理、短波狀上攀交錯層理、假前積層等層理構(gòu)造;水力跳躍作用形成的侵蝕和軟沉積物變形構(gòu)造等局部識別標志和旋回坎綜合識別標志。理想條件下,超臨界沉積物重力流作用在垂向上由下至上形成礫質(zhì)旋回坎、礫質(zhì)流槽-凹坑沉積充填、砂質(zhì)不穩(wěn)定逆行沙丘沉積、砂質(zhì)分層沉積和沙紋沉積及正常沉積的有序組合。旋回坎可分為侵蝕型和沉積型,從盆地邊緣向盆地中心,呈現(xiàn)侵蝕型向沉積型的演化。超臨界沉積物重力流作用沉積演化過程主要受流體沉積物濃度、流體流量、沉積物粒度、沉積速率等內(nèi)部因素和地形坡度、坡折帶位置、水深及可供侵蝕的沉積物特征等外部因素的綜合控制。超臨界沉積物重力流作用的相關(guān)研究加深了對沉積物重力流水道形成機理、深水塊狀粗碎屑成因、重力流沉積演化過程的認識;現(xiàn)階段關(guān)于超臨界沉積物重力流的流體動力學特征、沉積識別標志及形成演化過程的系列問題還有待深入研究。
[Abstract]:Supercritical sediment gravity flow refers to the high-density flow which occurs frequently under the action of hydraulic jump mechanism when the Froude number is greater than 1 in deep water environment and moves along the underwater slope to the center of the basin. The sedimentary identification marker of supercritical sediment gravity flow is the main one. It includes the stratified structure formed by traction blanket, such as post-accumulated bedding, short-wave cross-climbing bedding, pseudo-pre-accumulated bedding, erosion formed by hydraulic jumping and deformation structure of soft sediment, and comprehensive identification marks of cyclic ridge. Up to the top, a conglomerate cyclic ridge, a conglomerate flow trough-pit sedimentary filling, an unstable sand retrograde dune deposit, a stratified sand deposit, a sand ripple deposit and an orderly combination of normal deposits are formed. The process of sedimentary evolution is mainly controlled by internal factors such as fluid sediment concentration, fluid flow, sediment grain size, sedimentary rate, topographic gradient, slope break location, water depth and erodible sediment characteristics. Mechanisms, genesis of deep-water massive coarse debris, and understanding of the sedimentary evolution of gravity flow. At present, the hydrodynamic characteristics of supercritical sediment gravity flow, sedimentary identification markers and a series of problems in the process of formation and evolution need to be further studied.
【作者單位】： 中國石油大學地球科學與技術(shù)學院;海洋國家實驗室海洋礦產(chǎn)資源評價與探測技術(shù)功能實驗室;
【基金】：國家重大科技專項(2016ZX05006-007) 中央高校基本科研業(yè)務費專項資金項目(14CX06070A)資助
【分類號】：P512.2

【參考文獻】

相關(guān)期刊論文 前10條

1 YANG Tian;CAO Yingchang;WANG Yanzhong;;A new discovery of The Early Cretaceous Supercritical Hyperpycnal Flow Deposits on Lingshan Island,East China[J];Acta Geologica Sinica(English Edition);2017年02期

2 操應長;楊田;王艷忠;張少敏;王思佳;張青青;王心懌;;深水碎屑流與濁流混合事件層類型及成因機制[J];地學前緣;2017年03期

3 袁靜;梁繪媛;梁兵;董道濤;閔偉;宋t，

本文編號：2195531